"A person who thinks only about building walls, wherever they may be, and not building bridges, is not Christian. This is not in the gospel," the Pope told journalists.

Asked if American Catholics should vote for Trump, Francis demurred.

"As far as what you said about whether I would advise to vote or not to vote, I am not going to get involved in that. I say only that this man is not Christian if he has said things like that."

This is unprecedented in American politics that a sitting Pope would speak so critically of a current White House contender.

From what I understand, Trump is currently polling about 20 points ahead of the rest of the GOP pack in terms of evangelicals. Now, evangelicals aren't Catholic, but many Christians across many denominations look to the Pope as the "voice" of Christianity. I'll be curious to see if this impacts the numbers in the upcoming South Carolina primary on Saturday.

Watch The Donald's Twitter feed for his next rant. How much can you go off on the Pope?